This invention relates to ringing devices for telephones and other applications and, more particularly, to a device for controlling the volume of sound emitted by a gong of a ringer.
A common form of bell or ringer used in telephones comprises a gong which emits sound upon vibration of the gong. An electromagnet operative in response to a telephone ring signal, drives a striker or clapper against the gong. A spring retracts the striker from the gong. Periodic motion of the striker during a striking of the gong induces the familiar sound of a telephone ring.
A feature commonly found on telephones is a volume control, or damper, which interacts with the striker and/or gong to reduce the intensity, or volume, of the sound. By way of example, one form of damper employs a mechanical constraint on the amplitude of the displacement of the striker. Another form of damper employs a spring which is pressed against a peripheral portion of the gong under control of a manually operated lever of the volume control. The same lever may also be used to operate the mechanical constraint on the striker displacement amplitude so that a telephone ringer can readily be constructed with either one or both of the foregoing exemplary devices for the control of the sound volume.
Further examples of telephone ringing devices are presented in the following U.S. Patents. U.S. Pat. No. 1,437,924 of Todd discloses a leather damping element which can be placed between a tapper and bell so as to reduce the intensity of sound.
U.S. Pat. No. 2,590,500 of Bredehoft et al discloses sound adjustment of a ringer by varying the spacing of gongs relative to a clapper. U.S. Pat. No. 2,643,634 discloses the deadening of sound by use of a wedge positioned on the end of a leg for insertion between a bell and a clapper. U.S. Pat. No. 2,692,380 of Cleaveland discloses an additional weight cantilevered on an armature which carries the bell clapper. U.S. Pat. No. 2,808,019 of Houdek,Jr. discloses a double armed damper for contacting gongs in a dual-gong ringer for reducing the volume of the sound. U.S. Pat. No. 4,054,870 discloses an eccentric mounting of a gong which mounting provides for a change of distance between a clapper and the gong to accomplish a volume control.
An important consideration in the process of manufacturing a ringer, such as a ringer for telephone use, is the amount of steps, particularly labor intensive steps, which need be taken in the fabrication of the ringer. In the foregoing art, a substantial number of parts are assembled to accomplish the function of sound volume control. This presents a problem in that the manufacturing process is not as economical as would be desired.